Primary epithelial-myoepithelial carcinoma of the pituitary gland

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Epithelial-myoepithelial carcinoma of the nasopharynx: A case report and review of the literature

Background

Epithelial-myoepithelial carcinoma (EMCa) is a rare low-grade malignant tumor that most commonly occurs in the salivary glands, with approximately 320 cases having been reported worldwide. Here, we report the third case of EMCa occurring in the nasopharynx. Rare cases in the breast, pituitary gland, lacrimal gland, nose, paranasal sinus, nasal cavity, trachea and bronchus, lung, and even the pleura mediastinalis have also been reported. Histopathology and immunohistochemistry are useful for confirming the diagnosis of EMCa, which is characterized by biphasic tubular structures composed of inner ductal and outer clear myoepithelial cells and stains for different markers in each layer. However, because of the rarity of EMCa, the clinicopathological characteristics and treatment of these patients remain unclear.

Case presentation

We report a rare case of EMCa of the nasopharynx. A 51-year-old man presented with a 5-month history of pain while swallowing and aggravation accompanied by right ear tinnitus lasting for 1 month. Nasopharyngoscopy and magnetic resonance imaging (MRI) of the nasopharynx and neck revealed a 5.6 cm × 3.4 cm × 3.1 cm mass in the nasopharyngeal space, invasion of the right cavernous sinus, and lymph node enlargement in the right retropharyngeal space. On 17 April 2019, based on the histopathological and immunohistochemical features, a final diagnosis of EMCa of the right nasopharynx was made. The patient underwent concurrent chemoradiotherapy (CCRT), and his symptoms were relieved after treatment. On 10 January 2022, nasopharynx MRI and biopsy revealed local recurrence, but chest and abdominal computed tomography (CT) showed no obvious signs of metastasis. The local recurrence-free survival (LRFS) period was 33 months.

Conclusion

To the best of our knowledge, this is the third reported case of EMCa in the nasopharynx and the only case of EMCa in the nasopharynx treated with CCRT, and a partial response was achieved. Therefore, to improve the quality of life and prognosis of patients with unresectable tumors, we believe that CCRT is a suitable option. Further clinical observations are required to elucidate the pathophysiology and prognosis of EMCa.

Salivary gland tissues and derived primary and metastatic neoplasms: unusual pitfalls in the work-up of sellar lesions. A systematic review

PURPOSE

Salivary gland (SG) tissue and derived neoplasms may occur in the sellar region. As the current literature is mostly limited to case reports, the puzzling case of an inflammatory SG removed by transsphenoidal surgery (TS) and mimicking a prolactinoma prompted us to perform the first systematic review of these unusual conditions.

METHODS

A systematic literature search was conducted according to the PRISMA guidelines. Forty-four individual cases-non-neoplastic enlarged salivary glands (NNESG, n = 15), primary benign (n = 7) and malignant (n = 8) ectopic salivary tumours (ST) and sellar metastasis from eutopic primary ST (n = 14)-were suitable for the analysis of clinical, radiological and pathological characteristics. Therapeutic outcome was reviewed as a secondary endpoint.

RESULTS

All cases were diagnosed after surgery. NNESG commonly affected young and/or female patients, typically leading to headaches and hyperprolactinemia and originating close to the neurohypophysis. Submucosal SG should be excluded before concluding to an intrasellar NNESG after TS. No gender or age predominance was found for primary ectopic ST, which present as large tumors, with histological phenotypes similar to common ST. Hypopituitarism and diabetes insipidus were more frequent in ST than in NNESG. NNESG and benign ectopic ST rarely recur. Malignant ectopic ST should be distinguished from secondary localizations of eutopic ST reaching the sella by contiguity or metastatic spread; both share a frequent unfavorable outcome.

CONCLUSION

Sellar neoplasms derived from SG are rare but misleading conditions and pituitary dysfunction is likely to be more common than currently reported. Appropriate pathological evaluation and multidisciplinary approach are required.

Primary Pituitary Adenoid Cystic Carcinoma: A Rare Salivary Gland-Like Tumor in the Sella

Adenoid cystic carcinoma (ACC) is a tumor of the exocrine glands that originates primarily from the minor and major salivary glands, nasopharynx, and lacrimal glands. ACC grows slowly but is locally aggressive and prone to recurrence. It is uncommon for ACCs to develop in the pituitary gland as a primary tumor. We present a case of primary pituitary ACC extending to the sphenoid sinus resembling an invasive adenoma in a 71-year-old woman with a history of nasal epistaxis. We reviewed other reported cases of pituitary ACCs with retrospective validation of whether the tumor was primary or not. The intrasellar tumor exhibited MYB rearrangement with enlargement and destruction of the sella turcica and dural tears toward the sphenoid sinus, which would be consistent for a tumor originating from the pituitary gland. Including our case, only four intrasellar and one suprasellar ACC have been confirmed as primary tumors. All intrasellar ACCs had the characteristic of some form of invasion of neighboring structures with evidence of hyperprolactinemia. ACC could develop in the pituitary gland as a form of salivary gland-like tumor derived from the ectopic salivary gland rests. ACCs rarely arise from the pituitary gland; however, the accurate determination of primary occurrence is difficult because of the invasive nature of these tumors, and the anatomical relationship with the sphenoid sinus and the cavernous sinus. Excessive bleeding from the tumor or unexpected internal carotid artery injury should be avoided during surgery for primary and secondary pituitary ACC.